Self-protecting valve



Nov. l0, 1953 E. G. ANDERSON SELF-PROTECTING VALVE Filed March 28 1951 .1 M H y INVENTOR. ELMER G. ANDERSON Patented Nov. 10,1953

UNITED STATES PATENT OFFICE (Granted under Title 35, U. S. Code (1952),

sec. 266) 2 Claims.

` The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes Without the payment of any royalty thereon in accordance with the provisions of the act of March 3, 1883 (22 Stat. 625), as amended by the act of April 30, 1928 (45 Stat. 467, 35 U. S. C., 1946 Ed. Sec. 45).

This invention relates to valves, especially to valves in which an elastic diaphragm is used in connection with a valve seat as a closing mechanism. A typical eld of application for valves of this `kind is in hand-operated valves such as those used in lavatory xtures. This application is a continuation-in-part of my copending application for patent on a diaphragm valve, No. 18,189, led March 31, 1948, now abandoned, from which it differs, however, in some important ways.

The object of this invention is primarily to provide in a valve means for preventing shock or water hammer which is usually associated With valves When they are closed quickly. Another object is to provide means for protecting the valve itself from shock or damage when closed suddenly. Another object is to provide means for slowing up the new of fluid through the valve gradually regardless of the rapidity of closing of the valve. Another object is to provide means for preventing oscillation or fluttering of the valve closing elements when the flow through the valve is irregular. Another object is to provide the iiexibility required in the valve for preventing shock and at the same time to prevent leakage.

What constitutes my present invention is described in the specifications following in reference to the accompanying drawing and succinctly deiined in the appended claims.

In the drawing, Fig. 1 is a section principally along the longitudinal axis of a preferred form of embodiment of the essential features of my invention. I

Fig. 2 is a partial section of some of the same parts shown in Fig. 1, but in a partly open position for comparison with Fig. 1 which shows the parts in closed position.

Fig. 3 is a dissected View of shock-absorbing parts of my invention shown in Fig. 1, including an additional seetionalized View supplementing the section shown in Fig. 1.

Referring to Fig. 1, my invention consists of a valve body I with an inlet 2 and an outlet. The outlet, shown for example as a spout 3 extends into the body of the valve in a channel 4 terminating in a valve seat 5. Anannular ledge or shoulder 6 is formed inside the valve body to provide an opening 'I best shown in Fig. 1 surrounding the valve seat 5.

A soft, yielding diaphragm 8 is clamped against the ledge 6 by a Valve closure cap 9 which is threaded into the valve body l at In. A gasket Ii is clamped between cap S and shoulder 6 to hold diaphragm 8. Diaphragm S is sealed against shoulder e by gasket I I so that liquid cannot pass from the interior I2 of valve body I past diaphragm 3 into the interior of cap 9.

A valve stem I3 with threads I4 is operated by the conventional handle I5. A plunger I6 is carried in a hole Il in valve stern I3. Plunger I6 is enlarged at the outer end, preferably into a rounded or mushroom-shaped surface lwhich is in contact with diaphragm 8. held in hole Il by a retaining ring I9 against the pressure of a spring 2li. A washer 2I is optionally provided at the end of spring 26. An adjusting screw 22 is threaded into the bottoni of hole I1 at the location 23 in stem I3.

The rounded surface I8 of plunger I6 is, under some circumstances, hollowed out in the center to provide a holding recess 24 into which a projection 25 fits. Other convenient arrangements for securing the center of diaphragm 8 to the center of plunger surface I8 such as a conventional machine screw can also be used.

In the design of this valve the portion of the area of diaphragm 8 exposed outside the circumference of valve seat 5 is proportioned to fulll three conditions. bility in diaphragm 8 to avoid excessive stress and fatigue in repeated bending incidental to opening and closing the valve. Another is to provide a cross-sectional channel area around seat 5 substantially equivalent to that inside seat 5 for carrying the valve flow without undue restriction. The other is to provide an area of diaphragm subject to the pressure of fluid in the interior I2 of valve body I suicient to develop a considerable force for opposing the pressure of spring 2B when the valve is closed.

Spring 20 is designed to be appropriate to the iiuid pressure in the valve. The strength of spring 20 should be sufficient to hold diaphragm 8 down on seat 5 to close the valve under normal pressure conditions. Then if the valve is closed quickly and a pressure surge is developed, the increased force on diaphragm 8 overcomes the force of spring 20 and holds the diaphragm oif the seat 5 momentarily permitting some leakage of fluid thus relieving the pressure surge. A valve when changed from one pressure to another may need to have different springs 20, each designed Plunger I6 is;

One is to provide ample flexi.

for the pressure with which it is to be used. For example, if spring 20 and diaphragm 8 are in balance for operation at 50 pounds per square inch working pressure, and the working pressure is increased to 100 pounds per square inch, spring 20 will have to be increased in strength to avoid leakage if the valve is to permit the relief, of pressure surges of less than twice the normal pressure.

Relatively small changes in working pressure and relatively small changes in relief pressure.

. can be accomplished by adjusting screw 22 by turning it in the threads inside 230i valvef stem I3. The threaded end of screw 22 is slotted for a screwdriver as shown in Fig. 3. Thus screw 2-2 can be adjusted with a screw driver through the inside 23 of valve'stem I3 by removing screw 24 which holds handle I5 in place on-valve stem. I3.

The suppression of oscillation resulting from water hammer in the valve is aided by plunger I6 which iits closely in hole Il in valve stem- I3. Plunger I E, when lubricatedzbyoilf, grease, or water in hole Il acts as a dashpot when moved by pressure of springv 20 or diaphragm 8; The kind of oscillation often occurring in Valves of ordinary construction, especially when the parts are loosely fitted is prevented by the dashpot or, damping action of plunger I6 as it moves against the inelastic resistance-of fluidY escaping between the plunger and; the. containing wall. The combination of spring-20 and plunger I6 Yprovides complete impulse relief and damping, the-spring permitting movement of diaphragm and opening of the Valve. in response to excess pressure and plunger I6 absorbing energyv which could contribute toY oscillation.

1. In a valve, thel combination of a valve seat, a: flexible diaphragm closure member thereof, a

chamber, a spring-lcadedplunger operable-within said dash-pot to move for a limited distance in axial relation to Said Valve-stem and operable v upon said flexible diaphragm closure member to valve stem provided with a concentric dash-pot 40 seat.

2. In a valve, the combination of a valve seat,

Va flexible4 diaphragm closure member therefor,

a valve stem having a concentric dash-pot chamber therein, a plunger closely tted withinV said dash-pot chamber and adapted to move a limited distance within said chamber in axial relation to said valve stem, said plunger including a shank extending through a liquid-sealed opening in the end of said valve stem toward said valve seat, a head on said shank to engage said flexible diaphragm closure member, resilient means in said dashfpot chamber positioned to urge said plunger toward said valveV seat, said dash-pot chamber being liquid-filled to provide a damping action upon Vmovementof said plunger, and means for moving said valve stem toward and away fro said valve4 seat. Y

ELMER G. ANDERSON.

References Cited' inthe le of this patent Great Britain of 1941 

